Re: varptr to structs returns bad pointer value

[vuott@xxxxxxxxxxxx]

Private Extern myFunction(data As Pointer) In "mylib"

Public Struct myStruct
    result As Long
    msg As String
End Struct

Private myData As Struct Mystruct

Public Sub doit2()
  
  myFunction(VarPtr(myData))
  
End

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3 mar 2025, 09:17 da vuott@xxxxxxxxxxxx:

> He should try keyword "Struct" (obviously with Global declaration of variable structure), not "New".
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> 3 mar 2025, 01:51 da jussi.lahtinen@xxxxxxxxx:
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>> Oh yes, the problem confirmed.
>>
>> This raises the error correctly:
>>
>> Dim a As New myStruct
>> Print VarPtr(a)
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>> The interpreter is confused, because there is a public declaration, which is overdriven locally.
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>> Jussi
>>
>> On Mon, Mar 3, 2025 at 2:44 AM Jussi Lahtinen <>> jussi.lahtinen@xxxxxxxxx>> > wrote:
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>>> If I remember correctly structures cannot be declared locally, they must be at least private... so "mydata = new myStruct" might not be valid. And as Vuott said there is a missing keyword, which isn't even accepted within a function. So... maybe this just creates object instead of structure.
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>>> Anyway, some error should be raised.
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>>>
>>> Jussi
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>>> On Mon, Mar 3, 2025 at 2:24 AM <>>> vuott@xxxxxxxxxxxx>>> > wrote:
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>>>> He>>>>  >>>> should>>>>  >>>> try>>>> :Private Extern myFunction(data As Pointer) In "mylib"Public Struct myStruct    result As Long    msg As StringEnd StructPrivate myData As Struct MystructPublic Sub doit2()    myFunction(VarPtr(myData))  End
>>>> ----------------------------------------------------------------------------------
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>>>> 2 mar 2025, 22:43 da >>>> jussi.lahtinen@xxxxxxxxx>>>> :
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>>>>>>
>>>>>>
>>>>>> No this does not pass the correct pointer, I am trying to pass a      generic structure, I want to use pointers.
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>>>>> I see, it wasn't clear from the example code you gave.  I agree with your implementation plan.
>>>>>  
>>>>>
>>>>>>
>>>>>> I am sorry but varptr(xxx)    should return a pointer to the      actual memory containing the structure.
>>>>>>
>>>>>>
>>>>> I agree, but this isn't in the documentation and it seems it is not implemented [cannot find it under void SUBR_varptr(ushort code)
>>>>> ]. For the reasons Benoit knows, this is not raising error either. I don't know enough about the implementation details to say more.
>>>>> Maybe this can be added.
>>>>>
>>>>> Jussi
>>>>>  
>>>>>
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